Need some help with a SQL command

I am relatively new to wriring code in SQL. I have written a query that evaluates Coupons used with Items sold in the same transaction.. The query I have written works very well, but I would really like to skinny down the data that is returned.

For Example, Cou A, was used to sell Item 1, Cou B was used to sell Item 1, and coupon A was used to sell Items 2.

I need to figure out how to exclude certain records based on existence of multiple criteria. In this case, Cou B, Item 1 is a good transaction, and thus can be removed. Cou A Item 1 is suspect as well as Cou B Item 2.

If I wrie the code like this, I think the following will happen

Select *
from Coupon c, Sales S
where c.customer = s.Customer and
c.Coupon <> A
or S.Item <> 2

this would return all 3 of the records

Select *
from Coupon c, Sales S
where c.customer = s.Customer and
c.Coupon <> A
and S.Item <> 2

This would not return any records,

Select *
from Coupon c, Sales S
where c.customer = s.Customer and
c.Coupon <> A

Would return only one record,

Select *
from Coupon c, Sales S
where c.customer = s.Customer
and S.Item <> 2

would only return one records as well.

Can anybody point me in the right direction.

There would be several other combinations of Coupon and Item that I would want to remove from the tabls

Thanks

Casey Received on Sat Jun 17 2006 - 01:01:41 CDT